#region License
// Copyright 2008-2009 Jeremy Skinner (http://www.jeremyskinner.co.uk)
// 
// Licensed under the Apache License, Version 2.0 (the "License"); 
// you may not use this file except in compliance with the License. 
// You may obtain a copy of the License at 
// 
// http://www.apache.org/licenses/LICENSE-2.0 
// 
// Unless required by applicable law or agreed to in writing, software 
// distributed under the License is distributed on an "AS IS" BASIS, 
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
// See the License for the specific language governing permissions and 
// limitations under the License.
// 
// The latest version of this file can be found at http://www.codeplex.com/FluentValidation
#endregion

namespace FluentValidation.Attributes {
    using System;
    using System.Globalization;
    using Resources;

    /// <summary>
    /// Defines the resource key to be used for a particular property validator. 
    /// </summary>
    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
    public class ValidationMessageAttribute : Attribute {
        public string Key { get; set; }
        public string Message { get; set; }

        public static string GetMessage(Type type) {
            var attribute = (ValidationMessageAttribute)GetCustomAttribute(type, typeof(ValidationMessageAttribute), false);

            if (attribute == null) {
                throw new InvalidOperationException(string.Format("Type '{0}' does does not declare a ValidationMessageAttribute.", type.Name));
            }

            if (string.IsNullOrEmpty(attribute.Key) && string.IsNullOrEmpty(attribute.Message)) {
                throw new InvalidOperationException(string.Format("Type '{0}' declares a ValidationMessageAttribute but neither the Key nor Message are set.", type.Name));
            }

            if (!string.IsNullOrEmpty(attribute.Message)) {
                return attribute.Message;
            }
            string message;
            try
            {
                message = DefaultResourceManager.Current.GetString(attribute.Key, CultureInfo.CurrentCulture);
            }
            catch 
            {
                throw new InvalidOperationException(string.Format("Could not find a resource key with the name '{0}'.", attribute.Key));
            }
            return message;
        }
    }
}